dal031.relay.arandomserver.com has no MX records.
Question and response
Question
dig dal031.relay.arandomserver.com. MX
Answer
The response has no answer records.
Authority
arandomserver.com. 1800 SOA fay.ns.cloudflare.com. dns.cloudflare.com. 2397962920 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0